The limitation we are having is that we cannot have a dynamic URL on the FinalURL field, this way instead of having one ad for the 1000 products, we would need to have 1000 ads, as we cannot use the dynamic flags.

You can put strings, prices, numbers, and even a countdown to a specific date/time in your ad. Replacements can occur in ad titles and description lines, but you cannot perform replacements using this feature on the display or final URLs.